<%@ page import="java.sql.Connection" %>
<%@ page import="java.sql.DriverManager" %>
<%@ page import="java.sql.PreparedStatement" %>
<%@ page import="java.sql.ResultSet" %><%--
  Created by IntelliJ IDEA.
  User: cc
  Date: 2020/10/2
  Time: 10:46
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%
request.setCharacterEncoding("utf-8");
String username=request.getParameter("username");
String password=request.getParameter("password");

//加载数据库驱动
    Class.forName("com.mysql.jdbc.Driver");

    //建立数据库连接
    String url="jdbc:mysql://localhost:3306/book";
    Connection connection = DriverManager.getConnection(url,"root","root");

    //sql 模板
    String sql="select * from user where username=? and password=?";
    //使用PreparedStatement对象执行sql语句
    PreparedStatement ps=connection.prepareStatement(sql);

    ps.setString(1,username);
    ps.setString(2,password);

    ResultSet rs=ps.executeQuery();

    if(rs.next()){
//表示登陆成功
      out.print("登录成功");
      session.setAttribute("username",username);
    response.sendRedirect("home.jsp");
    }else{
        //表示登陆失败
      out.print("登录失败,3秒后自动跳转登录页面...");
    response.setHeader("refresh","3;url=login.jsp");

    }

    %>
